Fuel unit



Dec. 18, 1962 R. w. ERIKSON FUEL UNIT Filed Sept. 30. 1959 2Sheets-Sheet l Inn L'kson;

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FUEL UNIT Filed Sept. 30. 1959 2 Sheets-Sheet 2 1\ s kg N IN V EN TOR.

ioberz, Zfl 521725027 United States Patent Ofifice 3,069,177 PatentedDec. 18, 1962 3,069,177 FUEL UNIT Robert W. Erikson, Rockford, Ill.,assignor to Sundstrand Corporation, a corporation of Illinois FiledSept. 30, 1959, Ser. No. 843,528 1 Claim. (Cl. 277-93) This inventionrelates to a pump and more particularly to a pump of the gear type.

It is a general object of the present invention to produce a new andimproved pump of the character described.

It is a more specific object of the invention to produce a new andimproved pump of the gear type which is capable of operating over longerperiods without leaks or other difliculties which would necessitaterepair or replacement of parts.

It is still another object of the invention to produce a pump of thecharacter described in the preceding paragraph which includes a shaftrotatably mounted in the housing for rotating the gears of the pump andincluding a new and improved seal between the shaft and the housingtoprevent leakage of oil along the shaft and ultimately out of thehousing.

Other and further objects and advantages of the present invention willbe readily apparent from the following description and drawings, inwhich:

FIG. 1 is a flow diagram of a pump embodying the present invention;

FIG. 2 is an enlarged detail view of the shaft seal of the presentinvention;

FIG. 3 is a top plan view of a pump embodying the invention;

FIG. 4 is a longitudinal sectional View taken along line 44 of FIG. 3;and

FIG. 5 is a transverse sectional view taken along the line 55 of FIG. 3.

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail one specific embodiment, with the understanding that the presentdisclosure is to be considered as an exemplification of the principlesof the invention and is not intended to limit the invention to theembodiment illustrated. The scope of the invention will be pointed outin the appended claims.

Referring now to the drawings, there is shown a pump particularlyadapted for pumping fuel from a tank or other supply and supplying itunder pressure to a burner nozzle. The oil burner pump shown includes acasing provided with a cap 11 at one end thereof secured by bolts asshown to the body 12 of the casing. The cap 11 is hollow to provide areservoir 13 and in the reservoir there is located a cylindrical screen14 for preventing solid particles in the oil from entering the pumpingmechanism. At the top of the casing there is an inlet port 15 and analternate inlet port 15a is provided at the bottom of the casing. Eitherof the inlets may be used depending upon which is more convenient, andthe particular installation, and the inlet not in use may be closed by asuitable threaded plug.

Rotatably mounted in the casing 10 is a drive shaft 16, rotation ofwhich serves to rotate a first stage gear type pump 17 and a secondstage gear type pump 18, the first stage pump 17 being provided with aninternally contained ring gear 19 meshing with an externally containedpinion gear 20 with the gears being faced so as to provide a spacetherebetween opposite the point of close mesh with said space beingoccupied by a crescent member 21. The sec 0nd stage pump is providedwith similar gears including a ring gear 19a, a pinion 20a, and crescent21a. The shaft 16 is provided with a shaft seal generally indicated at22 to prevent leakage along the shaft and the details of this seal willsubsequently be described fully.

The first stage pump 17 is provided with an intake 23 2 and a discharge24 with the discharge being returnable either to the reservoir 13 or tothe tank from which the oil is drawn through the medium ofa pipe 25connecting I the discharge to the reservoir or through a discharge port26. A threaded plug 27 may be used to determine the final disposition ofthe discharge of the first stage. When the plug is in the positionshown, the discharge of the first stage is through the port 26 to tank,while when the plug 27 is removed and a similar plug is used to blockthe port 26, discharge is to the reservoir.

The first stage pump 17 acts primarily as a lift pump to bring oil fromthe tank or other place of storage to the reservoir 13 and its purposeis to maintain the reservoir 13 full of oil. It will be noted that theintake of the first stage pump is located at the top of the reservoir.Hence, it will serve to draw ofi air or foam from the reservoir so thatthe lower portion thereof is always filled with solid oil. The secondstage pump =18 draws its oil from the bottom portion of the reservoirand as it is this oil which is ultimately delivered to the burnernozzle, the advantage of the described locations for the intakes of thefirst and second stage pumps becomes apparent. Thus, the second stageintake 30 is located as shown in FIG. 1 near the bottom of thereservoir. The second stage pump discharge 31 is directed to a burnershut-off valve 32 which controls a burner port 33 connected to theburner. The valve 32 is similar to the cut-off valve shown in theErikson Patent No. 2,763,336 and includes an inlet chamber 34 to whichthe discharge line 31 is connected and a plurality of vertical passages35 opening at one end to the inlet chamber 34 and at the other end to anoutlet chamber 36. Oil under pressure supplied by the second stage pumpis directed to-the outlet chamber 36 and when the pressure issufficient, the valve 37 slides upwardly within the sleeve 37a againstthe opposition of spring 3811. The sleeve 37a is held in position by aretainer spring 33. The tension of spring 38a acting in opposition tothe pressure may be adjusted by the knobs 39 against which one end ofthe spring bears.

The valve 37 is carried at the lower end of a piston slidable in thesleeve 37a and the piston walls are provided with openings 40 connectingto an annular groove 41 formed at the exterior side walls of the pistonand that annular groove may be moved to communicate with the inletchamber 34 when the piston moves upwardly sufficiently in response toincreasing pressure. As the interior 42 of the shut-off valve isconnected to drain by means of the pipe 43, movement of the pistonupwardly to a point establishing communication between the inlet chamber34 and the interior of the valve through the medium of the grooves andopenings 40, 41 serves to limit the pressure of oil delivered to theburner nozzle. The pressure may be checked from time to time through themedium of gauge port 44 which connects as shown to the second stagedischarge line 31.

As indicated earlier, novel shaft seal means are provided for preventingleakage of oil along the shaft 16 from the area of the pumps 17 and 18and ultimately out of the right-hand end of the casing. Referring now toFIG. 2, it will be seen that the shaft seal 22 includes a floating ringof low friction material such as nylon, having a clearance 51 from theshaft of the order of .005 inch or even greater, and thus is free toadjust its position automatically so that its face 52 can engage theface 53 of the adjacent portion of the housing. A pin 54 extends throughthe shaft 16 and into suitable slots 54a provided in the ring 50 so asto rotate the same with the shaft. Covering the ring 5%) is a springsupporting cap 55 against which one end of a compression spring 56bears, the other end of the spring bearing against a corresponding cap57 covering a leaded bronze ring 58. The bronze ring is provided with aface 59 bearing against a correspending sealing face 60 provided on aring housing member 61 sealed to the housing 12 by O-ring 64. A secondO-ring 65 provides a seal between the shaft and the leaded bronze ring58 and the ring housing member 61 is maintained within the recess andthe housing by removable snap ring 66. A drain line 67 connects therecess housing the sealing ring to the drain line 43 as shown.

As indicated earlier, the ring 50 is floating by virtue of the clearancepreviously described and thus is more or less self-adjusting to the faceof the housing. The O- ring 65 does not supply the sole driving forcebetween the shaft 16 and the rotating bronze seal 58 as a good deal ofthe driving force is supplied through the medium of the spring 56 whichis rotated through its contact with the upper surface of the ring 50which is, as previously noted, pinned to the drive shaft.

I claim:

A rotating seal of the character described comprising a housing having ahollow therein, a shaft rotatably supported in said housing andextending through the hollow, oppositely facing annular seating areas inthe housing and surrounding the shaft at each end of the hollow, a nylonring encircling but spaced from the shaft loosely to surround the sameand having an annular face bearing against one seating area, meansproviding a driving engagement between said nylon ring and the shaftincluding a pin extending through said shaft and into a slot provided insaid nylon ring to allow said nylon ring to freely and automaticallyadjust its position in sealing engagement with said one seating area, asecond ring having an annular sealing face bearing against the otherseating area in sealing relationship therewith, a sealing meansinterposed between said second ring and said shaft, and a spring in thehollow compressed between said nylon ring and said second ring toprovide a driving connection between said nylon ring and said secondring for rotating the latter with the shaft, to urge said annularsealing face into engagement with said last mentioned seating area andto maintain the axial position of said shaft in said housing.

References Cited in the file of this patent UNITED STATES PATENTS1,859,436 Durdin May 24, 1932 1,862,887 Durdin June 14, 1932 2,277,196Arf Mar. 24, 1942 2,606,045 Forges Aug. 5, 1952 2,619,040 Maisch Nov.25, 1952 2,758,548 Rockwell Aug. 14, 1956 2,836,440 Brumagim May 27,1958 2,853,020 Hollinger et a1 Sept. 23, 1958 2,882,830 McDufIie Apr.21, 1959 2,892,413 Erikson June 30, 1959

